1. Field of the Invention
The present invention relates to plasma display device and a method for driving the same.
2. Description of the Related Art
A plasma display device is a display device that uses plasma generated by gas discharge to display characters or images. It includes, depending on its size, hundreds of thousands to millions of pixels arranged in a matrix pattern. Such a plasma display panel (PDP) is classified as a direct current (DC) type or an alternating current (AC) type according to its discharge cell structure and the waveform of the driving voltage applied thereto.
The DC PDP has electrodes exposed to a discharge space, and accordingly, it allows a DC to flow through the charge space while a voltage is applied. Therefore, such a DC PDP problematically requires a resistance for limiting the current. On the other hand, the AC PDP has electrodes covered with a dielectric layer that forms a capacitor to limit the current and protects the electrodes from the impact of ions during discharge. Accordingly, the AC PDP has a longer lifetime than the DC PDP.
In general, one frame of the AC PDP is divided into a plurality of subfields, and each subfield includes a reset period, an address period, and a sustain period.
The reset period is for initializing the state of each discharge cell so as to facilitate an address operation on the discharge cell, and the address period is for selecting turn-on/turn-off cells (i.e., cells to be turned on or off) in a panel and accumulating wall charges to the turn-on cells (i.e., addressed cells). The sustain period is for causing a discharge for displaying an image on the addressed cells.
In order to perform the above-noted operations, sustain pulses are alternately applied to the scan electrodes and the sustain electrodes during the sustain period, and the reset waveforms and scan waveforms are applied to the scan electrodes during the reset period and the address period. Therefore, a scan driving board for driving the scan electrodes and a sustain driving board for driving the sustain electrodes are separately needed, and in this case, a problem of mounting the driving boards on a chassis base may exist, and the cost increases because of the separate driving board.
Therefore, for combining the two driving boards into a single combined board, schemes of providing the single board at an end of the scan electrode and extending an end of the sustain electrodes to reach the combined board have been proposed. However, when the two driving boards are combined as such, the impedance component formed at the extended sustain electrodes is increased.